Derivatives - Summary of Primary Net Hedging Positions and Corresponding Fair Values (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Derivative [Line Items]
Currency Hedged (Buy/Sell), Gross Notional Value, Net	$ 27,643	$ 21,018
Currency Hedged (Buy/Sell), Fair Value, Asset/(Liability), Net	954	264
Forward Exchange Contracts [Member] | U.S. Dollar/Japanese Yen [Member]
Derivative [Line Items]
Currency Hedged (Buy/Sell), Gross Notional Value, Net	9,014	7,191
Currency Hedged (Buy/Sell), Fair Value, Asset/(Liability), Net	610	920
Forward Exchange Contracts [Member] | U.S. Dollar/South Korean Won [Member]
Derivative [Line Items]
Currency Hedged (Buy/Sell), Gross Notional Value, Net	10,122	9,254
Currency Hedged (Buy/Sell), Fair Value, Asset/(Liability), Net	48	(521)
Forward Exchange Contracts [Member] | U.S. Dollar/Euro [Member]
Derivative [Line Items]
Currency Hedged (Buy/Sell), Gross Notional Value, Net	2,500	2,806
Currency Hedged (Buy/Sell), Fair Value, Asset/(Liability), Net	205	(85)
Forward Exchange Contracts [Member] | U.S. Dollar/U.K. Pound Sterling [Member]
Derivative [Line Items]
Currency Hedged (Buy/Sell), Gross Notional Value, Net	1,261	1,767
Currency Hedged (Buy/Sell), Fair Value, Asset/(Liability), Net	40	(50)
Forward Exchange Contracts [Member] | U.S. Dollar/Taiwan Dollar [Member]
Derivative [Line Items]
Currency Hedged (Buy/Sell), Gross Notional Value, Net	4,746
Currency Hedged (Buy/Sell), Fair Value, Asset/(Liability), Net	$ 51